Caster



oct. 26,1926. 1,604,729

J. A. WEIGEL CASTER )Filed Jan.` 2. 1925 @j Mfg?" MyW Patented ct. 26,1926.

AU Arran STATES JOHN A. WEIG-EL, 0F HAMILTON, OHIO.

CASTER.

Application jled January 2, 1925. Serial No. 1.

Y This invention relates to improvements in` casters of the swiveledwheel type.

a One object of the invention is to provide an anti-friction bearingcaster in which certain of the anti-friction elementsiact to lock theparts together in swiveled relation.

Another object is toV provide two sets of anti-friction deviceseach. ofdifferent type, respectively 4for sustaining vertical and lat eralthrusts. t

Another object is to provide avery durable type ofV anti-friction devicefor the caster, adapted to receivevertical thrusts, in which `thefriction between the elements on the bearing surfaces is reduced to aminimum. Y. h

Another object is to provide a caster in which vertical movement of thevassembled parts is. provided for to. compensate for wear of the verticalthrust receiving antifriction elements.

Another object is to provide improved fastening means for holdingtheroller `shaft against Vrotation in its' bearings.

Another object of the invention is to provideV a device which maybecheaply manufactured and.. which can be easily assembled.

lOther objects, advantages and certain features ofthe invention will bedisclosed in the drawings forming part of this application andy in saiddrawings:

Figure 1 is a side elevation of my improved caster. t

Figure 2` is an end view takenat right angles to Figure 1. A

Figure 3 isa vertical section on line 3-3 of Figure 2, showingthefassemble-d details.V

Figureilis asection on line-llof FigureB, showingthe. arrangement oftheconicalroller bearings.. y v t Figure 5 is asimilar view on line 5-5 ofvFigure 3, Vshowing the relation of the ball bearings.Y y

Figure (iis a section .through the roller on line 6.-6 of Figure 1,illustrating the man ner of locking the roller shaft against rota tion.t l

Figure Zlshows a modification of `the roller bearing` assembled usingoppositelyv related semi-circular grooves. y n y Figure Sishows amodified fornrof roller bearingfin which only one of the bearing, seatsis conical. l

The details of construction of the preferred ,embodiment of invention`are best shown inY Figuredwhichrepresents a form:

of caster duty.

The caster/,comprises an upper cupi-dement 1 as an attachment member,and a lower wheel frame 2. The cup element as a housing member is ofhollow cylindrical configuration, is closed atthe upper endand hasmarginal outwardly extending attaching flanges 3 withv openings throughwhich fastening particularly adapted for heavy" devices are interposedto secure the housing.

A recess 4C is thusprov-ided within which the upward cylindrical bodyportion 5 of theL wheel44 frameQ loosely engagesfor swiveling the lowermember t0 the upper. The body of `this wheelf frame has` extendingdownwar-diy,therefrom spacedlegsl() at `the lower end of which arealigned openings or bores lltraversed by a shaft 12upon which isdisposed the wheel-13. Rollerbearings 14 surround the shaftwithinthejhub bore of the wheel and longitudinalitranslation of the same ispreventedby the side walls of the legs, see Figure 6. s

Itis `desirable tol non-rotatably secure theshaft 12 againstdisplacement, and novel means is hereinprovided for this purpose.` asfollows: e

The outer faces of the legs y10 are provided with longitudinallyextending parallel` spaced ribs 15 acting both as strengthening ribs andas means for securing the shaft againstrotation.' The ends of theshaft'extend beyond the legs and between the parallel ribs, see Figure6, and one end ofthe shaft has a. bore. 20, preferably diametric,adapted fto register or align with correspondingly aligned cross bores2l, one in each rib. All bores are alignable and whenaligned a split keyor cotterpin 22 is passedl therethrough and ythe projecting ends of thekpin bent as shown to prevent accidental removal. The shaft is th-uspositively locked y against displacement or rotation.

It will be noted,however,that one rib maybe used, with the pin 22passing through a singlel opening therein and then through the diametricopening of the shaft, or alug may be used in a similar manner, the pinpassingthroughthe lug and then through theidiametric opening, in theshaft.V

Vertical orlongitudinal thrusts are sustainedV andthe wear ofanti-friction devices is reduced to arninimum inthe Afollowing nevelmanner e e The endlwallzofthe cavity isinachined asl atABO, see .Figure3, jto provide a downwardly convergent conical roller bearing set whichis opposingly related to a similar seat 31 on the end face of thecylindrical body portion 5 of the wheel frame.

Arranged between the opposing conical bearing surfaces thus formed, andagainst the same is an annular series of radially disposed substantiallycone-shaped'thrust receiving rollers 33 and said rollers are held inspaced relation by a circular spacer element 35 having radial inwardlyconvergent substantially V-shaped projections 3G, each adapted to liebetween two adjacent rollers with opposing edges of adjacent projectionssubstantially parallel with the surface of the rollers providinginwardly convergent openings into which the rollers loosely lit, thearms aetingas separators., rlhe rollers are thus inwardlyT convergentlydisposed.

By the use of conical rollers, the wear of said rollers and bearingsurfaces is reduced, inasmuch as the opposingly related surfaces orseats conform to that of the bearing rollers at all points, so thatthere is no tendency for any portion of the roller to travel at greateror less speed than another.

rIhe housing and wheel frame are secured together in assembled relationand adapted for rotation by the following device:

rIhe recesso has a circumferential groove of rectangular cross sectionadapted for opposing registration. with a companion groove 4l ofsemi-circular cross section to form a ball race. After the introductionof the wheel frame within the recess of the housing, balls 42 areintroduced into the channel through a radial bore 43 which is afterwardsclosed by a screw plug 44, the plug being locked against rotation by anut 45.

The radius of this semi-circular groove is slightly greater vthan thatof the ball and 1the longitudinal vertical dimension of the bearing isnecessary and this clearance for vertical playis provided between thehousing and wheel frame, the circumferential rectangular groove in thehousing being elongated vertically or in a direction parallel with therotative axis of the wheel frame. Thus, as wear progresses between therollt-Srs and their conical bearing seats, the housing is permittedtoride toward the wheel frame while at the Sametime proper lateralthrust g bearing contact is maintained.

In Figure 7, I have illustrated a modification in which -twosemi-circular grooves 47, 48 respectivelyjin the housing andv wheelframe are used, the radius -of the grooves being slightly greater thanthat of the balls, thus allowing slight axial play to compene sate forwear in theroller bearing. In Figure S, I show a modification in which aflat `bearing surface 30a is provided in lieu of the conical surface 30for the reason that a flat surface is more easily finished. Tocompensate, the angle of the conical seat 3la is increased and the axesof the rollers are tilted from the horizontal and no longer lie at aright angle to the rotative axis of the caster; V

Inasmuch as the tendency of the conical rollers is to ride outwardlyinto contact with the vertical wall of the recess as the Wheel framerotates, each roller bearing has an outer substantially spherical convexface for reducing friction, these spherical faces having virtually apoint contact. i

The radius of curvature of the annular series of balls is preferablyslightly greater than that of the annular series of cone rollers. Therollers are Vdesigned to sustain the greater part of the weight and theballs to receive side thrusts, the opposingly rela-ted grooves and ballstherein also, acting to secure the f frame and housing together inswiveledv relation.

Having described my invention, what I claim is:

l.l A caster comprising a housing, a wheel frame projecting loosely androtatably within the housing, opposingly related grooves in housing andwheel frame, respectively a rectangular groove elongated in axialdirection and a circular groove of less diameter than the lengthwisedimension of the rectangular groove,`an annular series of balls withinthe groove as thrust receiving elements acting to hold the housing andframe in assembled relation, and cone-shapedrollers radially arrangedbetween the housing and wheel frame for receiving vertical thrusts.

2. In a caster, a housing having a cavity therein, said cavity having arectangular circumferential ball groove elongated axially of the housingand disposed at a right angle to its axis, and having a radial passageleading into the groove, a wheel frame having a cylindrical projectionloosely engaged in the cavity, and having a circular groove of lessdiameterthan the long dimension of the rectangular groove adapted forregistration with said rectangular groove, a series of balls as lateralthrust bearings disposed within the grooves for holding the housing andframe in assembled orswiveled relation', spaced substantially conicalradially disposed rollers disposed between opposing walls of the cavity,and frame projection, and a circular spacer member having radial armsextending loosely between'the rollers.

3( A caster comprising, an attaching housfing having a cylindricalrecess therein, a

Wheel frame having a cylindrical portion extending loosely into therecess, an annular series of balls interposed between the Walls of thehousing recess and the .cylindrical portion for providing a lateralthrust bearing therebetween, said bearings snugly seated Within oneelement and vertically movable on the other to prevent any binding dueto end thrusts on said bearings and roller bearings radially arrangedbetween lthe horizontal end faces of the frame cylinmy name.

JOHN A. WEIGEL.

